The present disclosure relates to high-voltage circuit interrupters. More specifically, the present disclosure relates to a high-voltage circuit interrupter having an improved density gas blast for quenching arcs.
A gas-insulated high-voltage circuit interrupter typically contains a male contact, a female contact that is capable of moving relative to the male contact along an axis, a heating chamber for accommodating a supply of quenching gas, and a heating channel positioned to direct the quenching gas toward the contacts. With this type of interrupter, the pressure of the quenching gas within the heating chamber is generating when an arc occurs between the two contacts as the two contacts disconnect. As the contacts disconnect, high pressure gas is forced up the heating channel into the heating chamber. There, the quenching gas already in the heating chamber is pressurized and, after the pressure reaches a high enough level, the quenching gas is forced out of the heating chamber through the heating channel toward the arc as it approaches current zero, thereby extinguishing the arc. The interrupter may also include an insulating nozzle positioned to direct the pressurized quenching gas toward the arc.
In order to quench the arc, a quenching gas such as sulfur hexafluoride (SF6) or a combination of gases is used. The quenching gas is compressed during the disconnecting of the contacts and subsequently extinguishes the arc, thereby interrupting the current flow at a zero crossing.
Interrupters using self-blowing arc quenching, or “inhale/exhale” interrupters, have several disadvantages. Depending upon the geometry and stroke position of the contacts, a larger portion of the energy created by the arc is lost to female-side exhaust rather than pressurizing the quenching gas in the heating chamber. Additionally, the gas forced into the heating chamber or “inhaled” into the heating chamber increases the temperature of the quenching gas already stored in the heating chamber, thereby reducing the density of the quenching gas and the overall associated quenching capabilities as the quenching gas is subsequently “exhaled” toward the arc.